Pianists Elizabeth Joy Roe and Greg Anderson. (Lisa-Marie Mazzucco)

Anderson and Roe, the piano duo who played at the National Gallery on Sunday afternoon, are the very model of complete 21st-century musicians. They fuse classical and pop music into a blend of high artistry and skillful entertainment; they write informative program notes; they talk to the audience from the stage, passing the mic back and forth. That they are crack pianists goes without saying.

Let’s stop thinking of “entertainment,” or pop-music elements, as a trick to which classical musicians have to resort in the unceasing attempt to win over new audiences. Let’s start accepting it as part of the landscape — and not a cheap, selling-out part, either. Mozart, in his day, was “entertainment”; Beethoven was “entertainment”; Liszt and Chopin certainly were; and even Wagner was. The idea that “entertainment” and “popular” are dirty words, sullying the purity of our art, is a recent one and dovetails, exactly and unsurprisingly, with the decline of classical music’s popularity. If a new generation finds ways to redefine the exercise — to incorporate, as this duo did, Michael Jackson and Radiohead on a program alongside Stravinsky’s “Rite of Spring” — that’s only beneficial, to the artists and the field. 

Beneficial, that is, as long as they make a case for it. And they did. Greg Anderson and Elizabeth Joy Roe, to grace them with their full names, offered a Halloween-themed program, the first half themed “Dance” and the second “Night,” that was also fiercely musically ambitious. Playing the first half of “Rite of Spring” as their second piece, in a ferocious, thundering four-hand arrangement that left the West Garden Court shivering with echoes, was something of a shot across the bow: It was hard to reach anything more climactic or challenging after that, though they certainly tried. (Saint-Saëns’s “Danse Macabre: Bacchanal,” brilliant though it was, paled a bit in comparison, in part because the echoing room blunted its details.) 

You could say they were trying a bit hard, and certainly every aspect of their program was thoroughly considered, down to their continuous switching of instruments so that you never knew who was going to sit where next. Self-awareness, to the point of self-mockery, is supposed to be a hallmark of the current age: Roe, appearing in a stunning gown, deadpanned, “This is actually my Halloween costume.” But then they used that self-awareness in their performance, building in a cognizance of their physical proximity to each other as an extension of the seductiveness and transgressiveness of the tango in Astor Piazzola’s “Oblivion,” in which Roe stood and plucked at the strings before sitting by Anderson and weaving her arms across his to reach some notes. (Piazzola’s “Libertango” was the bring-down-the-house encore.) 

Some might criticize this self-awareness, because slickness is a mark, to some audiences, of selling out. I think, though, that most critics would have been brought around, and even found that there was just as much power in an arrangement of Radiohead’s “Paranoid Android” as in a sweet and jewel-like performance of a ballet from Gluck’s “Orpheus and Eurydice.” The afternoon was, finally, swept away by the whirling power of the final piece, Ravel’s “La Valse.” Where does classical music fit in the 21st century? It’s an ongoing exploration, but this may be a step on the way to finding out.